Spoilers ahead for Avengers: Infinity War.
Thanos isn't your usual Marvel nemesis. Then again, even after 19 films in Disney's superhero universe, it's not as if he's had much strong competition. Aside from the puckish Loki and tragic Killmonger, most Marvel villains have been pretty forgettable. Now, after years of build up (we first caught a glimpse of Thanos in 2012's The Avengers) he finally took center stage in this summer's Avengers: Infinity War.